The incident happened at the Emmaus Home Charity Shop in the High Street on Friday at 3.30pm.

The men entered the store and one of them then distracted a staff member while the other opened the till and stole around £180.

As the thieves tried to leave the shop the staff member tried to prevent them from escaping and she was hit and pushed to the floor. Acting Detective Sergeant Pete Coley, of Colchester CID, said: “These were clearly two desperate thieves who have targeted a charity.

“When fleeing with the money they have then not hesitated to assault the brave staff member who has tried to thwart their escape. Thankfully her injuries are minor.

“We are determined to find these men and get them arrested.

“We urgently need to hear from witnesses who were in the area of Colchester High Street that day who might have seen the thieves running from the scene.”

One man is described as white, approximately 5ft 5in tall, of stocky build with a chubby face. He was wearing a beige beanie hat with a navy blue or black line round the rim, a beige long sleeved polo shirt, blue jeans and dirty white trainers. He was also carrying a black carrier bag.

The other is white, approximately 5ft 2in tall, of thin build, with dark hair that came over his ears. He was wearing a blue knitted jumper, blue jeans and black trainers.